Crystal Structure and Electronic Properties of Graphite-Like C7N Phase from First-Principles Calculations

2011 ◽  
Vol 268-270 ◽  
pp. 940-945
Author(s):  
Qian Ku Hu ◽  
Hai Yan Han ◽  
Hai Yan Wang ◽  
Qing Hua Wu
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Density Functional Method ◽  
Functional Method ◽  
Stable Phase ◽  
Ambient Conditions ◽  
Electronic Band ◽  
Structural And Electronic Properties

The structural and electronic properties of graphite-like C7N compound have been calculated by using first-principles pseudopotential density functional method for ten possible C7N configurations, which are deduced from graphite and hexagonal boron nitride unit cell. The calculated total energy results show that the configuration C7N-I with AA stacking sequence along the c-axis based on hexagonal BN structure has been shown to be the most stable structure. From the calculated electronic band structures and electron density of states, the monolayer and bulk phase of C7N are expected to show insulating and metal states, respectively. The graphite-like C7N phases have been predicted to be a stable phase at ambient conditions by formation energy and elastic constant calculations. A critical pressure of about 41 GPa is expected for a synthesis of cubic C7N phase from this graphite-like C7N.

scholarly journals Structural and Electronic Properties of Orthorhombic Phase Bi2Se3 Based On First-Principles Study

2019 ◽  
Vol 16 (2) ◽  
pp. 77 ◽  
Author(s):  
Muhammad Zamir Mohyedin ◽  
Afiq Radzwan ◽  
Mohammad Fariz Mohamad Taib ◽  
Rosnah Zakaria ◽  
Nor Kartini Jaafar ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Computer Code ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Exchange Correlation ◽  
Percentage Difference ◽  
Structural And Electronic Properties

Bi2Se3 is one of the promising materials in thermoelectric devices and very useful out of environmental concern due to its efficiency to perform at room temperature. Based on the first-principles calculation of density functional theory (DFT) by using CASTEP computer code, structural and electronic properties of Bi2Se3 were investigated. The calculation is conducted within the exchange-correlation of local density approximation (LDA) and generalized gradient approximation within the revision of Perdew-Burke-Ernzerhof (GGA-PBE) functional. It was found that the results are consistent with previous works of theoretical study with small percentage difference. LDA exchange-correlation functional method is more accurate and have a better agreement than GGA-PBE to describe the structural properties of Bi2Se3 which consist of lattice parameters. LDA functional also shown more accurate electronic structure of Bi2Se3 that consist of band structure and density of states (DOS) which consistent with most previous theoretical works with small percentage difference. This study proves the reliability of CASTEP computer code and show LDA exchange-correlation functional is more accurate in describing the nature of Bi2Se3 compared to the other functionals.

scholarly journals HfS2 and TiS2 Monolayers with Adsorbed C, N, P Atoms: A First Principles Study

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 94
Author(s):  
Mailing Berwanger ◽  
Rajeev Ahuja ◽  
Paulo Cesar Piquini
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Molecular Species ◽  
First Principles ◽  
Density Functional ◽  
2D Materials ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Localized Levels

First principles density functional theory was used to study the energetic, structural, and electronic properties of HfS 2 and TiS 2 materials in their bulk, pristine monolayer, as well as in the monolayer structure with the adsorbed C, N, and P atoms. It is shown that the HfS 2 monolayer remains a semiconductor while TiS 2 changes from semiconductor to metallic behavior after the atomic adsorption. The interaction with the external atoms introduces localized levels inside the band gap of the pristine monolayers, significantly altering their electronic properties, with important consequences on the practical use of these materials in real devices. These results emphasize the importance of considering the interaction of these 2D materials with common external atomic or molecular species.

First Principles Study on Structural and Electronic Properties of LiFeSO4OH Cathode Material for Lithium Ion Batteries

2014 ◽  
Vol 510 ◽  
pp. 33-38 ◽  
Author(s):  
F.W. Badrudin ◽  
M.S.A. Rasiman ◽  
M.F.M. Taib ◽  
N.H. Hussin ◽  
O.H. Hassan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cathode Material ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Density Of State ◽  
Functional Theory ◽  
Structural And Electronic Properties

Structural and electronic properties of a new fluorine-free cathode material of polyanionichydroxysulfates, LiFeSO4OH withcaminitestructure are studied using first principles density functional theory. From the calculated result, it reveals that antiferromagnetic configuration is more stable compared to ferromagnetic and non-magnetic configuration. Meanwhile, the density of state calculation divulges that this material exhibited large d-d type of band gap and would behave as a Mott-Hubbard insulator. Thus, this behaviour can lead to poor electronic conductivity.

Theoretical Study of CN Radicals Chemisorption on the Electronic Properties of BC2N Nanotube

2017 ◽  
Vol 48 ◽  
pp. 38-48 ◽  
Author(s):  
Batoul Makiabadi ◽  
Mohammad Zakarianezhad ◽  
Shahin Mohammadzamani
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Method ◽  
Nbo Analysis ◽  
Band Gap Energy ◽  
Functional Method ◽  
Basis Set ◽  
Hybrid Density Functional ◽  
Cn Radicals ◽  
Covalent Nature

In this work, we have investigated the adsorption behavior of the CN radicals on electronic properties of BC2N nanotube (BC2NNT) by means of the B3LYP hybrid density functional method using 6-31G(d) basis set. The results show that CN radicals can be chemically adsorbed on the nanotube. Based on the energy analysis, the most stable position of CN radical on the nanotube is C1 site. Also, the C-side complexes are more stable than the N-side complexes. We investigated the effects of CN radicals adsorption on the electronic properties of the BC2N nanotube. According to our calculations, band gap energy of the BC2NNT decreases with increasing the number of CN radicals. It is predicted that the conductivity and reactivity of nanotube increase by increasing the number of CN radicals. Based on the NBO analysis, in all complexes charge transfer occurs from nanotube to CN radical. The AIM results show that, the Xtube…YCN interaction has covalent nature. Generally, The BC2N nanotube can be used to as sensor for nanodevice applications.

scholarly journals Structural and electronic properties of the spinel Li4Ti5O12

2019 ◽  
Vol 20 (46) ◽  
pp. 7-12 ◽  
Author(s):  
Sarantuya Lkhagvajav ◽  
Namsrai Tsogbadrakh ◽  
Enkhjargal Enkhbayar ◽  
Sevjidsuren Galsan ◽  
Pagvajav Altantsog
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Experimental Studies ◽  
First Principles Calculations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural And Electronic Properties ◽  
Hubbard U ◽  
Uv Visible

In this study, the structure and electronic properties of the spinel compound Li4Ti5O12 (LTO) are investigated both theoretical and experimental methods. The experimental studies of structural and electronic properties were performed by X-ray diffraction and UV-visible spectroscopy. The first principles calculations allowed to establish the relationship between the structure and electronic properties. The spinel type structure of LTO is refined by the Rietveld analysis using the X-ray diffraction (XRD). The band gap of LTO was determined to be 3.55 eV using the UV-visible absorption spectra. The Density functional theory (DFT) augmented without and with the Hubbard U correction (GGA and GGA +U+J0) is used to elucidate the electronic structure of LTO. We have performed systematic studies of the first principles calculations based on the GGA and GGA+U for the crystal structure and electronic properties of spinel LTO. We propose that a Hubbard U correction improves the DFT results.

scholarly journals First Principles Study on Structural and Electronic Properties of Cubic (Pm3m) And Tetragonal (P4mm) ATiO3 (A=Pb, Sn)

2020 ◽  
Vol 17 (2) ◽  
pp. 149
Author(s):  
Nurakma Natasya Md Jahangir Alam ◽  
Nur Aisyah Ab Malik Marwan ◽  
Mohd Hazrie Samat ◽  
Muhammad Zamir Mohyedin ◽  
Nur Hafiz Hussin ◽  
...  
Keyword(s):  
Cross Section ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Ferroelectric Materials ◽  
Lead Free ◽  
Electronic Band ◽  
Functional Theory ◽  
First Principles Study ◽  
Structural And Electronic Properties

Works are centered on exploring lead-free ferroelectric materials that have a comparable unique ns2 solitary pair electrons with Pb (II), for example, Sn (II) using the first-principles study. All counts were performed dependent on Density Functional Theory (DFT) that has been executed in CASTEP. GGA-PBE displays the most exact qualities for cross-section parameters concerning exploratory qualities for both cubic PbTiO3. In the interim, GGA-PBEsol functional is exact for tetragonal PTO. The electronic band structure and density of states show the presence of hybridizations between anion O 2p and cation Pb 6s/Sn 5s unique solitary pair in tetragonal PTO and SnTO stage.

scholarly journals Formation and Physical Properties of h-BN Atomic Layers: A First-Principles Density-Functional Study

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yoshitaka Fujimoto
Keyword(s):  
Boron Nitride ◽  
Physical Properties ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Hexagonal Boron Nitride ◽  
Defect Size ◽  
Functional Study ◽  
Density Functional Study ◽  
The Relationship

Hexagonal boron nitride (h-BN) atomic layers have attracted much attention as a potential device material for future nanoelectronics, optoelectronics, and spintronics applications. This review aims to describe the recent works of the first-principles density-functional study on h-BN layers. We show physical properties induced by introduction of various kinds of defects in h-BN layers. We further discuss the relationship among the defect size, the strain, and the magnetic as well as the electronic properties.

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